So the two cams each have their own TDC lock down. The exhaust uses the PD method of a keyed cam sprocket and a pin. The intake uses the VE method of a bar and slot in the end of the camshaft. I don't know how but the shims I ended up using were exactly the same as specified in my Bentley.
I unfortunately don't have a picture of it but I clamped a spare intake camshaft to the exhaust camshaft using worm gear hose clamps (being absolutely careful that I didn't touch any lobes on the new camshaft with the clamps or the spare camshaft). The clamps meshed the teeth together and aligned the two split gears on the exhaust camshaft. This allowed me to easily slip the intake camshaft into place.